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2 years ago

Simplify (3-6i) (-5+ i)

Mathematics

1 answer:

Tanya [424]2 years ago

5 0

Answer:

Simplifed using FOIL: -15+30t+(3-6t)i

Simplifed using distributive property: 15+30t+(3-6t)i

Step-by-step explanation:

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What is the sum of these expressions: (-3.5t - 4s + 4.5) + (-7.1 - 0.3s + 4.1t)

dmitriy555 [2]

-4.3s + 0.6t - 2.6 is the answer

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2 years ago

A dome of a building is in the form of a hemisphere from inside it was whitewashed at the cost of rupees 4989.60 if the cost of

Luda [366]

Answer: $249.48\ m^2; 369.168\ m^3$

Step-by-step explanation:

Given

Cost of white-washing =Rs. 4989.60

Rate =20 per meter square

So, inside area of = $\dfrac{4989.60}{20}=249.48\ m^2$

The surface area of dome= $4\pi\ r^2=249.48$

$4\times 3.142\times r^2=249.48\\r^2=\frac{249.48}{4\times 3.142}=19.85\\r=4.455\ m$

The volume of air in the dome $V=\frac{4}{3}\pi r^3$

$V=\frac{4}{3}\cdot 3.142\cdot (4.45)^3\\V=369.17\ m^3$

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2 years ago

What is the value of b ?

HACTEHA [7]

Two polynomials are equal if the coefficients are equal.

$x^3+(3+b)x^2+(3b-2)x-6\\\downarrow\qquad\ \ \downarrow\qquad\qquad\ \ \ \ \downarrow\\x^3\ +\ \ 6x^2\ \ \ \ +\ \ \ \ \ 7x\ \ -\ 6\\\\x^3\to1=1\\x^2\to3+b=6\\x\to3b-2=7\\constans\to-6=-6\\\\3+b=6\ \wedge\ 3b-2=7\\\\3+b=6\ \ \ |-3\\b=3\\\\3b-2=\ \ \ \ |+2\\3b=9\ \ \ \ |:3\\b=3\\\\Answer:\ \boxed{b=3}\to\boxed{B.}$

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2 years ago

C. How many pieces of siding need to be purchased? Justify your reasoning.

Mademuasel [1]

Answer:14025

Step-by-step explanation:

Because 25x33x17=14025

4 0

2 years ago

Read 2 more answers

Help please!! i don’t understand this one!

12345 [234]

Answer:

C, D

Step-by-step explanation:

This equation can be solved any of several ways. One that doesn't require much thought is using the quadratic formula.

For ax² +bx +c = 0, the solutions are ...

$x=\dfrac{-b\pm\sqrt{b^2-4ac}}{2a}$

In the given equation, a=2, b=11, c=5, so this becomes ...

$x=\dfrac{-11\pm\sqrt{11^2-4\cdot2\cdot5}}{2\cdot2}=\dfrac{-11\pm\sqrt{81}}{4}\\\\x=\dfrac{-11\pm9}{4}=\left\{-\dfrac{20}{4},-\dfrac{2}{4}\right\}=\{-5,-\frac{1}{2}\}$

The solutions are ...

C. x = -5

D. x = -1/2

_____

My personal favorite is using a graphing calculator. The solutions are the x-intercepts of the expression on the left. That is, where its value is zero, as the equation says.

5 0

2 years ago